m, t, s = map(int, input().split())
if t == 0:
    print(0)
else:
    div, mod = divmod(s, t)
    if mod != 0:
        div += 1
    nums = m - div
    if s == 0 :
        print(m)
    elif nums <= 0  :
        print(0)
    else:
        print(nums)
